UVA12689 Teaching Hazard

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=602&page=show_problem&problem=4427 [PDF](https://uva.onlinejudge.org/external/126/p12689.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12689/87372999599fd8ad8f4df145654312c2b175da6b.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12689/8480d2c90201adbb2d1c6319fa98eb45f77914af.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12689/507e1f8e6ec52e223548a82067d846d22d34f7ac.png)